DESCRIPTION: (Applicant's Abstract) We propose to investigate and develop an inexpensive and reliable method to determine the lipid and protein composition of tears that could be used both in the basic science laboratory and clinically in a diagnostic laboratory setting. Our approach would not only generate the detailed information needed for more precise diagnosis of dry eye conditions, but also provide the basis for development of more specific and effective categories for (and possibly therapies targeted directly to) the individual deficiencies that ' characterize the spectrum of dry eye disorders. More than 12 million people in the United States alone have been clinically diagnosed with some form of keratitis sicca or dry eyes. Although their symptoms are similar, the underlying causes are often unknown and no practical methodology for evaluating the composition of tears from such patients exists. To date, analysis of tear composition has been hampered by the minute sample sizes available and the technical inability to identify and measure the components of such a complex fluid at concentration scales of nanomoles or less. Capillary electrophoresis-electrospray ionization mass spectrometry (CE-ESI/MS) is a sensitive, relatively inexpensive method capable of analyzing samples 2 pl or less in size. Using micellar electrokinetic capillary chromatography techniques coupled with mass spectrometry detection, we plan to design and develop 1) a novel standard separation method for the lipids within tears and 2) a novel standard separation method for the proteins within tears. We will then investigate the use of these methods to develop standard lipid and protein component profiles of normal tears and identify specific component differences in the tears from two different dry eye models. The development of this technology to provide specific information on the complex disorder know as dry eye could provide relief to and enhance the quality of life of millions of patients for whom no reliable long-lasting therapy is currently available.